Why can't she let me go? does she have feelings for me that she doesn't want to deal with?

It sounds like you have put your life on hold over this girl. You need to walk away and find peace of mind with your own life. Don't hang around waiting. What are you going to do? Hang on forever? If you let go now you won't be kicking yourself a year or two years down the line wishing you had cut it way back when. Now is as good a time as any to find someone else and let her go! Good luck!